Middletown, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.5 °C (low) to 18 °C (high). Annual precipitation averages 1016 Millimeters. Middletown is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.9 °C | 2.9 °C | 55.12 mm |
| February | -5.1 °C | 5.7 °C | 54.61 mm |
| March | 0 °C | 11.8 °C | 72.64 mm |
| April | 6.1 °C | 18.7 °C | 105.41 mm |
| May | 12.1 °C | 23.8 °C | 116.33 mm |
| June | 17.1 °C | 28.6 °C | 116.59 mm |
| July | 19.3 °C | 30.7 °C | 111.25 mm |
| August | 18.2 °C | 30.2 °C | 82.04 mm |
| September | 13.4 °C | 26.4 °C | 93.73 mm |
| October | 7 °C | 19.8 °C | 81.03 mm |
| November | 0.9 °C | 12.1 °C | 71.37 mm |
| December | -4.1 °C | 5.3 °C | 55.88 mm |
| Annual | 6.5 °C | 18 °C | 1016 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |